Problem: Simplify the following expression: $q = \dfrac{-2a}{10} + \dfrac{-3a}{10}$
Explanation: Since the expressions have the same denominator we simply combine the numerators: $q = \dfrac{-2a - 3a}{10}$ Combine like terms: $q = \dfrac{-5a}{10}$ Simplify by dividing numerator and denominator by 5: $q = \dfrac{-a}{2}$